Brooding

Brooding is a Demon Hunter passive skill unlocked at Level 25, which grants 2% (increased from 1% in Patch 1.0.8) life regeneration per second. This will give a 40,000 hps Demon Hunter 800 hit points per second, or about 400 per tick. Hardcore Demon Hunters with much higher hit points will enjoy a proportionately greater life regeneration, potentially much more than can be obtained with life regen gear.

The skill's popularity shows the difference in the game modes very clearly.

Brooding was initially a throwback to some of the earlier health systems in Diablo 3, when it and granted healing only if the Demon Hunter had been out of combat for 3 seconds. It was very seldom used in that form, and Patch 1.0.4 removed the "out of combat" time delay aspect and increased its popularity.

Brooding was not seen until it showed up in the Diablo III beta as a level 10 passive. Later it was moved to level 18 and in Beta Patch 13, Brooding was changed to a level 19 passive. When passives were reorganized for Beta Patch 14, Brooding was moved up to level 25 and nerfed: granting 1% of Life per second instead of 2%.